Fire dampers of both the hinge and curtain type are known in the art, some including means for sealing the area between the blade or curtain and the frame to prevent the passage of smoke or fire through a building conduit as evidenced by the prior Jenkins Pat. No. 3,990,464. The Loewenheim U.S. Pat. No. 2,489,915 discloses a hinged-type damper which includes an auxiliary closure element adapted to be moved independently of the damper itself. Curtain dampers including metal sealing strips or loops are disclosed in the patents to Lowe Nos. 2,964,036 and 2,996,063, Beck No. 3,504,883 and Alley No. 3,575,229. The Johnson U.S. Pat. No. 3,165,050 discloses a blade-type damper which includes an axle arrangement for the pivotal blade which co-acts with a slot on the frame to maintain the closed blades tight against the frame. As further disclosed in the Johnson patent, fusible links which melt in the presence of fire or high heat to enable the damper to close are well known in the prior art.